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Biology Grade 11 > Biology Exam Review > Flashcards

Biology Exam Review Flashcards

1
Q

Why do cells divide in mitosis?

A
  1. Growth
  2. Repair
  3. Reproduction
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2
Q

What happens in Interphase?

A

There are three parts of interphase, Gap 1, Synthesis, Gap 2.
In G1 and G2 the cell grows.
In synthesis, the genetic material is duplicated.
There are checkpoints to make sure DNA duplicated properly.
The genetic material is inside the nucleus (chromatin).

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3
Q

What happens in prophase I?

A

The chromosomes get paired, then condense. The spindle fibers form. The centrioles will move to opposite poles. Synapsis happens (Homologous chromosomes create tetrad which is 4 chromatids. Recombination/crossing over happens. The place/site they will cross over is called chiasma.

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4
Q

What happens in metaphase I?

A

The tetrads line up in/along the equator in a random assortment (independent assortment). The spindle fibres attach to the the pair of sister chromatids.

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5
Q

What happens in Anaphase I?

A

The sister chromatids do not separate here (differs from mitosis)
Although, the pairs of chromosomes move apart to opposite poles.

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6
Q

What happens in Telophase I?

A

Cytokinesis happens, creating two genetically different daughter cells.
Each daughter cell has half the number has half the number of chromosomes as the parent cell (haploid-n)

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7
Q

What happens in prophase II?

A

The nuclear envelope breaks and the spindle fibres start to form.

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8
Q

What happens in Metaphase II?

A

Chromosomes align in the along equator of the cell.

Spindle fibres attach to centromeres of sister chromatids.

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9
Q

What happens in Anaphase II?

A

Spindle fibres contract and pull sister chromatids apart.

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10
Q

What happens in Telophase II

A

Nuclear envelope assembles.
chromosomes decondense.
Spindle disappears.
Cytokinesis divides each cell into two.

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11
Q

What is the result of meiosis?

A

4 non identical haploid gamete cells.
1 copy of each chromosome
1 allele of each gene
Different combinations of alleles for different genes along the chromosomes.

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12
Q

What is Evolution?

A

The change in inherited traits in a population over time.

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13
Q

What is microevolution?

A

Small changes within a population or species. These changes happen over a short period of time.

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14
Q

What is macroevolution?

A

Large changes in organisms over a long period of time.

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15
Q

What is gene pool?

A

The total collection of alleles in a population at any one time. Gene pool can be measured by allele frequency.

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16
Q

What is population?

A

A population is a group of individuals of the same species living in the same place at the same time. Populations are the smallest unit that can evolve.

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17
Q

What are the non random changes of microevolution?

A

Natural Selection, Artificial Selection, Sexual Selection

18
Q

What are random changes in microevolution?

A

Mutations, Genetic Drift, Gene Flow.

19
Q

What are the four points of natural selection?

A
  1. Variation - There is Variation that already exists in a population.
  2. Competition/Struggle - overpopulation causes struggle for existence (food, water, territory)
  3. Environmental Selection - Environment selects fit variant
  4. Reproduction and Inheritance - The variation passed on to next generation
20
Q

What are adaptations?

A

A structural, physiological or behavioral trait that improves an organism’s fitness in it’s environment.

21
Q

What are structural adaptations

A

Anatomical changes in the shape or arrangement of particular features.
An example can be arrangement of teeth, shape of fins or beaks.
Another example is mimicry, mimicry is the ability of one species to resemble another species that may be dangerous to the prey.

22
Q

What are physiological adaptations?

A

adaptations that are associated with the changes in biochemical functions inside organisms.
For example spider webs, antibiotic resistance in bacteria.

23
Q

What are behavioral adaptations?

A

Behavioral adaptations are how organisms respond to their environments.
For example migrations.

24
Q

What is artificial selection?

A

Directed breeding in which individuals that exhibit a particular trait are chosen as parents of the next generation. Artificial selection is used to produce new breeds or varieties of plants and animals.

25
Q

What is sexual selection?

A

Favors selection of any trait that influences mating success of an individual.

26
Q

What is Intrersexual selection?

A

males compete to be chosen by females, females choose mates by physical or behavioral features (bright coloration or songs).

27
Q

What is Intrasexual selection?

A

Male to male competition, males compete amongst themselves.

Example, best fighting style, largest body size.

28
Q

What is sexual dimorphism?

A

Morphological differences between males and females of the same.

29
Q

What is allele frequency?

A

The frequency of the allele compared to the total alleles found in that population.

30
Q

What is the Hardy-Weinberg Principle

A

Allele frequency will not change from generation to generation as long as
1. The population size remains large
2. Mating opportunities are equal
3. No mutations occur
4. No migrations occur
5. No natural selection occurs.
(All individuals have an equal chance of reproducing)

31
Q

What is genetic drift?

A

When there are changes in allele frequency due to chance
An example is when a natural disaster happens - the survivors don’t survive because they were suited for the environment better, but rather because they were lucky. The alleles that are present in the survivors are only a (random) sample of those of the original population.

32
Q

How does genetic drift tend to fix alleles?

A

Genetic drift tends to fix alleles because they are the only allele left in the population meaning allele frequency is 100 percent. Although genetic drift doesn’t have to fix alleles. Genetic drift also reduces genetic diversity.

33
Q

What is bottleneck effect.

A

A dramatic, often temporary, reduction in population size. Only a small sample of alleles survives to establish the new population.
The surviving individuals often do not reflect the allele make up of the original population and due to that genetic drift happens.

34
Q

What is founder effect?

A

Founder effect is when a small number of individuals isolate themselves from their original population and establish a new one. The genetic variation will not be the same as the original population.

35
Q

What is gene flow?

A

Gene flow is the movement of alleles from one population to another by permanent migration or mating between populations without permanent migration.
Genetic information is shared between populations.
The difference between gene flow and genetic drift is that gene flow reduces the differences between populations because new alleles may be introduced to one population and alleles may be lost from another population.

36
Q

What is species biologically?

A

Species biologically is a group of similar individuals that are capable of interbreeding that produce fertile offspring.

37
Q

What is species evolutionary?

A

They are members of interbreeding groups or populations that are reproductively isolated from other groups and evolve independently

38
Q

What is speciation?

A

It’s the process by which new biological species arise.

39
Q

What are Reproductive isolating mechanisms?

A

Any behavioral, structural or biochemical trait that prevents individuals from reproducing successfully together.
Some are due to the traits of the organism
Some are due to environmental circumstances

40
Q

What is allopatric speciation?

A

Allopatric speciation is when populations of a species become geographically isolated. Often a physical barrier between two populations.

41
Q

What is sympatric speciation?

A

Its the evolution of populations within the same geographic area into separate species.
Gene flow is reduced between populations.

42
Q

What is adaptive radiation?

A

Adaptive radiation is the possible result of allopatric or sympatric speciation.
It’s when a single species evolve into a number of distinct/closely related species in one speciation event.
Each new species fills a different ecological niche
Usually occurs when a variety of new resources becomes available.
Increases biodiversity.

Biology Grade 11 (1 decks)

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