Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Unit 5 - Inheritance + Populations > Flashcards

Unit 5 - Inheritance + Populations Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Definition of chromatin?

A

Made of DNA and histone proteins

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

Definition of chromosome?

A

Made of chromatin. Each species has a different number of them and they contain all the genes for an organism.

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

Definition of gene?

A

A base sequence of DNA on a chromosome which codes for the amino acid sequence of a polypeptide or a functional RNA

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

Definition of locus?

A

The fixed position of a gene on a particular chromosome

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

Definition of an allele?

A

A different version of a gene

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

Definition of a diploid cell?

A

A cell containing 2 sets (homologous pairs) of each chromosome in the nucleus.

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

Definition of a haploid cell?

A

A cell containing one set of each chromosome in the nucleus.

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

Definition of a genotype?

A

The generic constitution of an organisms.

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

Definition of a phenotype?

A

The expression of the genetic constitution and its interaction with the environment.

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

What is a mutation?

A

A change to the DNA base sequence and can change the genotype. If the mutation is in the gametes this can be inherited.

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

What are homologous chromosomes?

A

They have the same genes, in the same gene loci, but can have different alleles. This is because one of the pair is maternal and the other is paternal.

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

Definition of homozygous?

A

When the allele on each homologous chromosome is the same.

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

Definition of heterozygous?

A

When the allele on each homologous chromosome is different.

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

Homozygous dominant=2 dominant

A

Homozygous recessive=2 recessive

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

Definition of recessive allele?

A

Only expressed in the phenotype when 2 copies are present (homozygous)

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

Definition of dominant allele?

A

Always expressed in the phenotype when present.

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

What does a gene being expressed mean?

A

Expression of a gene means how it is transcribed into mRNA and then how mRNA is translated into a protein.

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

P?
F1?
F2?

A

P - parental generation
F1 - offspring of the parents
F2 - offspring of the F1 generation

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

Definition of monohybrid inheritance?

A

The inheritance of a single gene on an autosomal (a chromosome that isn’t a sex chromosome)

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

Monohybrid crosses?

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

What ratio do monohybrid crosses of heterozygous parents always produce?

A

3:1

22
Q

Why are actual results of genetic crossed rarely the same as predicted results?

A

-Fertilisation of gametes is random
-May be a small sample
-Some alleles may give a selective advantage/selective disadvantage/be a lethal allele
-Epistasis
-Linked genes

23
Q

What are codominant alleles?

A

They are alleles that are both expressed in the phenotype when they occur in a heterozygous individual.
Therefore there are 3 phenotypes, created by just 2 alleles
A gene letter is used and superscript letters are used for the allele

24
Q

Genetic diagram for codominant alleles?

A
25
Q

What is meant by multiple alleles?

A

If a gene has more than 2 alleles in a population.
(You only have 2)

26
Q

Genetic diagram for multiple alleles?

A
27
Q

What is sex linked inheritance?

A

It is the inheritance of a gene found on the X or Y chromosome.

28
Q

What are the sex chromosomes:
Of males?
Of females?

A

Males - XY
Females - XX

29
Q

Why are X and Y chromosomes not homologous pairs?

A

The Y chromosome carries only sex genes but the X chromosome carries both sex genes and genes controlling other body characteristics.
Due to the Y chromosome being shorter, it does not have all of the same genes at the same gene loci as the C chromosome, so the C and Y chromosomes are not homologous pairs.

30
Q

Which sex is more likely to express the recessive alleles found on the sex chromosome and why?

A

Males because they only have 1 copy of the C chromosome so only need 1 copy of the recessive allele in their genotype to express the recessive phenotype, whereas females have 2 copies of the X chromosome so need 2 copies of the recessive allele in their genotype to express the recessive phenotype.

31
Q

Sex-linked inheritance crosses?

A
32
Q

What is a carrier?

A

Individuals who have 1 copy of a recessive allele for disease but do not express it in their phenotype because they’re heterozygous.

33
Q

What do sons inherit?

A

His X chromosome from his mother and his Y chromosome from his father

34
Q

What do daughters inherit?

A

X chromosome from his mother and an X chromosome from his father.

35
Q

What is a pedigree diagram?

A
36
Q

If a questions asks you what is the evidence that a phenotype is caused by a dominant or recessive allele?

A

Find 2 parents with the same phenotype who have offspring of the opposite phenotype. The parents must be heterozygous so whichever allele is expressed in their phenotype is dominant

37
Q

If a question asks you what is the evidence that the gene is found on the X chromosome?

A

Then normally only males will be affected in the diagram.

38
Q

What is dihybrid inheritance?

A

It is the inheritance of 2 different genes on different chromosomes at the same time.

39
Q

Dihybrid inheritance crosses?

A
40
Q

Dihybrid crosses of heterozygous parents always produce what phenotypic ratio?

A

9:3:3:1

41
Q

What is autosomal inheritance?

A

The inheritance of 2 or more genes carried on the same autosome (a chromosome that is not a sex chromosome).
Assuming no crossing over all the genes found on the same chromosome will be passed to gametes during meiosis to offspring.

42
Q

Autosomal linked crosses?

A
43
Q

Explaining the results of autosomal linked genetic crosses?

A

-Say which alleles are linked based on the information given
-State the gamete genotypes and phenotypes that would mainly be produced
-Say that crossing over would produce some gametes with the non-linked genes together. State these gametes genotypes.
-Say that fewer off spring with the non-linked phenotypes would be produced and state those phenotypes because crossing over is rare.

44
Q

Definition of epistasis?

A

When the allele of one gene affects or masks the expression of another gene.

45
Q

What is phenotype frequency?

A

How often a phenotype appears in a population.

46
Q

What is a genotype frequency?

A

How often a genotype appears in a population.

47
Q

What is an allele frequency?

A

How often a particular allele occurs within a population.

48
Q

What is the hardy Weinberg principle?

A

p^2 + 2pq + q^2 = 1. = genotype frequency
p + q = 1. = phenotype frequency
p^2 = homozygous dominant frequency
2pq = homozygous frequency
q^2 = homozygous recessive frequency
p = dominant allele frequency
q = recessive allele frequency

49
Q

What are the assumptions made by Hardy-Weinberg?

A

1) Mating is random
2) There is no immigration so no new alleles are introduced
3) There are no mutations so no new alleles are created
4) There is no selection so no alleles are favoured or eliminated
5) The population is large

50
Q

What are the assumptions made by Hardy-Weinberg?

A

1) Mating is random
2) There is no immigration so no new alleles are introduced
3) There are no mutations so no new alleles are created
4) There is no selection so no alleles are favoured or eliminated
5) The population is large

Biology (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions