Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

biology > Genetics, populations, evolution and ecosystems > Flashcards

Genetics, populations, evolution and ecosystems Flashcards

1
Q

What is a genotype?

A

The genotype is the genetic constitution of an organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a phenotype?

A

The phenotype is the expression of this genetic constitution and its interaction with the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 types of alleles?

A

recessive, dominant, codominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a recessive allele?

A

When both allele have to be present in order to be expressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a dominant allele?

A

Only one allele needs to be present in order to be expressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a codominant allele?

A

where 2 alleles are expressed equally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are polygenic traits?

A

traits that can be influenced by the environment e.g. skin colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an example of a codominance?

A

Sickle cell anaemia - mutation in haemoglobin causing red blood cells to have sickle shape instead of biconcave disc shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference of having sickle cell anaemia and having a trait of it?

A

people who are homozygous for the haemoglobin gene have the disorder meaning ALL of their red blood cells are sickle shaped ]
people who are heterozygous will have a sickle cell trait in SOME of their red blood cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is monohybrid inheritance?

A

when a trait is controlled by a single gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is dihybrid inheritance?

A

inheritance of 2 characteristics controlled by different genes - each have different alleles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are dihybrid crosses used for ?

A

predict the likelihood of offspring to inherit certain combination of 2 characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are sex linkages?

A

a trait which is coded for by a gene on a sex chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why are males more likely to express a phenotype for x-linked disorders?

A

Most sex linked traits are located on the X chromosomes with there being no equivalent locus on the Y chromosome. Therefore males will only have one copy of the allele, so it will be expressed even if recessive.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are autosomes?

A

any other chromosome different from sex chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the characteristics of genes on autosomes?

A

genes are linked due to staying close together during independent segregation
-the closer together they are the more closely linked as they are less likely to be split up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is epistasis?

A

when the allele of one gene is able to mask the expression of another allele of a different gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is recessive epistasis?

A

when the presence of a recessive allele masks the expression of another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is dominant epistasis?

A

when a dominant allele masks another locus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a chi-squared test?

A

a statistical test used to establish difference between observed and expected results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a gene pool?

A

the complete range of alleles present in a population

22
Q

What is a species?

A

A group of similar organisms that are able to reproduce and produce fertile offspring

23
Q

What is a population?

A

group of organisms of the same species that live in the same area at the same time and have to potential to interbreed

24
Q

What is allele frequency?

A

how often alleles occur in a population

25
What is the Hardy -Weinberg Principle used for?
to predict the frequency of alleles in a population - only true if there is no change in population
26
What is the Hardy - Weinberg equation?
p^2 * 2pq * q^2 =1
27
When does sympatric speciation occur?
when the population of organisms have been isolated due to a physical barrier, so the allele frequency changes and results in species that can no longer reproduce
28
When does allopatric speciation occur?
when allele frequency in a population of an organism changes without being pysically seperated, resulting in species that can no longer reproduce
29
What is a habitat?
the place where an organism lives
30
What is a population?
all of the organisms of the same species living in the same place at the same time, able to breed together
31
What is a community?
all of the populations of different species in the same place and time interacting with one another
32
What is an ecosystem?
includes all living and non-living organisms
33
What is the 'niche' of a species?
the role of a species in a habitat
34
What is adaptation?
a feature that members of a species have that increase their chances of survival/reproduction
35
What is an example of a physiological adaptation?
snakes producing venom to kill prey and ward off predators
36
What is an example of a behavioural adaptation?
penguins huddling together to keep warm, rotating penguins that are in the middle.
37
What is an example of an anatomical adaptation?
puffer fish puff up when they feel threatened to appear larger and be harder to eat
38
What is an adaptation to biotic conditions?
peacocks - use tails to attract mates otters - use rocks to break open clams
39
What is an adaptation to abiotic conditions?
40
What is a population?
all of the organisms of the same species in the same habitat at the same time
41
What is a community?
all of the populations of different species in the same habitat.
42
What is population size?
the total number of organisms of one species in a habitat. The population size can change due to the effect of various factors (availability of space, food etc).
43
What can cause variation in a phenotype?
-meiosis -mutations -random fertilisation
44
What is directional selection?
occurs when the environmental conditions change and the phenotypes best suited to the new conditions are more likely to survive
45
What is stabilising selection?
phenotypes with successful characteristics are preserved and those of greater diversity are reduced
46
What is disruptive selection?
both extremes of the normal distribution are favoured over the mean
47
What are limiting factors of a population?
Temperature - each species has a different optimum temperature that it is best able to survive at Light - this is a basic necessity of light, with the rate of photosynthesis increasing as light intensity increases pH - this can have an impact on the action of enzymes with each enzyme having an optimum pH that it can work at Water and humidity - in instances where water is scarce only small populations of adapted species will exist. Humidity affects transportation in plants and therefore only those that are adapted to environments where transpiration is high will survive.
48
What is carrying capacity?
the size of a population an ecosystem can hold
49
What is the difference between interspecific and intraspecific competition?
intraspecific competition - competition by the same species interspecific competition - where members of different species compete with one another for the same resources.
50
What is predation?
when one species (the prey) is caught and eaten by another species (the predator)
51
What is a predator - prey relationship?
-When the prey is eaten by the predator the population of the prey falls. -This results in the predator population growing, however means that more prey is consumed -Therefore the population of prey reduces and there is increased competition for the the prey between the predators -The lack of food for the predators means that the population falls meaning that less prey is eaten -This allows the population of the prey to recover and therefore the cycle occurs over in a oscillating manner
52
How do you use quadrats?
-randomly choose an area of investigation and section it off into a grid with coordinates -use a random number generator to pick your coordinates and place your quadrat there -count the number of species inside the quadrat -repeat multiple times (30+) -calculate the mean/average - multiply the amount of quadrats that fit into the grid with the mean number of species

biology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions