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CSIR NET Life Sciences Evolution And Behaviour Flashcards
50 question-and-answer cards covering Evolution And Behaviour as it is examined in CSIR NET Life Sciences. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Evolution And Behaviour deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
What is molecular divergence?
The accumulation of differences in DNA or protein sequences between two lineages over time after they split from a common ancestor; greater divergence generally indicates a more distant common ancestor.
Name common molecular tools used in phylogeny and identification.
DNA sequencing, PCR, DNA barcoding (e.g., COI, rRNA genes like 16S/18S), RFLP, RAPD, AFLP, microsatellites, and sequence alignment/phylogenetic tree software.
What is the difference between protein and nucleotide sequence analysis in phylogenetics?
Nucleotide analysis uses DNA/RNA sequences (more variable, good for closely related taxa); protein (amino acid) analysis is more conserved and useful for distantly related taxa because synonymous mutations don't change amino acids.
How do new genes and proteins commonly originate?
By gene duplication followed by divergence, exon shuffling, retrotransposition, horizontal gene transfer, gene fusion/fission, and de novo origin from non-coding DNA.
Explain gene duplication and divergence as a source of evolutionary novelty.
A gene is duplicated, freeing one copy from selective constraint; it can accumulate mutations and acquire a new function (neofunctionalization) or split the ancestral functions (subfunctionalization), producing gene families.
Define population, gene pool, and gene (allele) frequency.
A population is an interbreeding group of the same species in an area; the gene pool is the total of all alleles in that population; allele (gene) frequency is the proportion of a particular allele among all alleles at a locus.
State the Hardy–Weinberg principle.
In a large, randomly mating population with no mutation, migration, selection, or drift, allele and genotype frequencies remain constant across generations (genetic equilibrium).
Give the Hardy–Weinberg equations for a two-allele locus.
Allele frequencies: p + q = 1. Genotype frequencies: p² + 2pq + q² = 1, where p² = homozygous dominant, 2pq = heterozygous, q² = homozygous recessive.
List the five conditions that must be met for Hardy–Weinberg equilibrium.
(1) No mutation, (2) no gene flow/migration, (3) no natural selection, (4) random mating, and (5) infinitely large population size (no genetic drift).
How does natural selection change allele frequencies?
By differential survival and reproduction of genotypes: it increases the frequency of advantageous alleles and decreases deleterious ones. The rate depends on the selection coefficient (s) and the alleles' dominance.
What is random genetic drift and when is it strongest?
Random genetic drift is the change in allele frequencies due to chance sampling of gametes. Its effect is strongest in small populations and can cause loss or fixation of alleles regardless of fitness.
What is gene flow (migration) and its effect on populations?
Gene flow is the transfer of alleles between populations via movement of individuals or gametes. It tends to homogenize allele frequencies among populations and counteracts divergence/speciation.
Distinguish the founder effect and the bottleneck effect.
Both are forms of genetic drift. Founder effect: a new population started by a few individuals carries only a subset of the original gene pool. Bottleneck effect: a drastic population reduction randomly reduces genetic diversity.
What is adaptive radiation? Give an example.
The rapid diversification of a single ancestral lineage into many species adapted to different ecological niches. Example: Darwin's finches on the Galápagos Islands diversifying by beak/diet.
Distinguish prezygotic and postzygotic isolating mechanisms.
Prezygotic mechanisms prevent mating or fertilization (habitat, temporal, behavioral, mechanical, gametic isolation). Postzygotic mechanisms act after fertilization (hybrid inviability, hybrid sterility, hybrid breakdown).
Define speciation and name its main geographic modes.
Speciation is the formation of new, reproductively isolated species. Modes: allopatric (geographic separation), sympatric (within same area, e.g., polyploidy), parapatric (adjacent populations), and peripatric (small peripheral population).
What is the difference between allopatric and sympatric speciation?
Allopatric speciation occurs when populations are geographically separated, preventing gene flow. Sympatric speciation occurs without geographic isolation, within the same area (e.g., via polyploidy or disruptive selection).
What is convergent evolution? Give an example.
The independent evolution of similar traits in unrelated lineages due to similar selective pressures, producing analogous structures. Example: wings of birds, bats, and insects; streamlined bodies of sharks and dolphins.
What is sexual selection and its two main forms?
Selection arising from differential mating success. Forms: intrasexual selection (male–male competition for mates) and intersexual selection (mate choice, e.g., females choosing showy males like the peacock's tail).
What is coevolution? Give an example.
Reciprocal evolutionary change in two or more interacting species, each acting as a selective force on the other. Examples: flowering plants and their pollinators; predator–prey and host–parasite arms races.
Distinguish proximate and ultimate causation of behavior.
Proximate causation explains the immediate mechanism — how a behavior occurs (hormones, neural, developmental triggers). Ultimate causation explains why it evolved — its adaptive/fitness value and evolutionary history.
What is kin selection and Hamilton's rule?
Kin selection favors altruism toward relatives because they share genes. Hamilton's rule: altruism is favored when rB > C, where r = relatedness, B = benefit to recipient, C = cost to actor (concept of inclusive fitness).
Distinguish group selection, kin selection, and reciprocal altruism.
Group selection: traits favored because they benefit the group. Kin selection: altruism toward genetic relatives (inclusive fitness). Reciprocal altruism: helping non-relatives with expectation of future return ('you scratch my back...').
What is a biological clock / circadian rhythm?
An endogenous, self-sustaining internal timing mechanism (~24-hour circadian rhythm) that regulates physiological and behavioral cycles; entrained by external cues (zeitgebers like light) and controlled in mammals by the suprachiasmatic nucleus.
What this deck covers
The Evolution And Behaviour deck follows the CSIR NET Life Sciences Evolution And Behaviour syllabus — 6 chapters and 49 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 8.3 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 207 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Evolution And Behaviour flashcards FAQ
How many Evolution And Behaviour flashcards are in this CSIR NET Life Sciences deck?
50 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these CSIR NET Life Sciences flashcards free?
Yes. The preview here is free to read with no signup, and the full 50-card deck is free inside the Examius app.
What do the Evolution And Behaviour cards cover?
They follow the CSIR NET Life Sciences Evolution And Behaviour syllabus — 6 chapters and 49 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.