10. (a) Explain the following terms used in genetics:
(i) Gene - Leaving Cert Biology - Question 10 - 2013
Question 10
10. (a) Explain the following terms used in genetics:
(i) Gene.
(ii) Allele.
(iii) Genotype.
(b) There are four bases in DNA structure.
These are adenine (A), cytos... show full transcript
Worked Solution & Example Answer:10. (a) Explain the following terms used in genetics:
(i) Gene - Leaving Cert Biology - Question 10 - 2013
Step 1
Explain the following terms used in genetics: (i) Gene.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A gene is a unit of heredity, which is a functional section of DNA responsible for coding specific traits or functions in an organism. Genes are composed of sequences of nucleotides and can vary among individuals, leading to differences in traits.
Step 2
Explain the following terms used in genetics: (ii) Allele.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
An allele is an alternative form of a gene. Each gene can have multiple alleles which code for different variations of a trait. For example, a gene for flower color may have a purple allele and a white allele.
Step 3
Explain the following terms used in genetics: (iii) Genotype.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The genotype refers to the genetic makeup of an organism, specifically the combination of alleles it possesses for a given trait. This genetic composition can influence phenotypic expressions, which are the observable characteristics.
Step 4
There are four bases in DNA structure: (i) Name the bases at positions X and Y in the diagram.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The base at position X is Thymine (T) and the base at position Y is Cytosine (C).
Step 5
There are four bases in DNA structure: (ii) Where in a human cell would you expect to find most DNA?
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Most DNA in a human cell is found within the nucleus, where chromosomes containing the genetic material are located.
Step 6
There are four bases in DNA structure: (iii) Name the molecule that carries the DNA code to the ribosomes.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The molecule that carries the DNA code to the ribosomes is called messenger RNA (mRNA).
Step 7
There are four bases in DNA structure: (iv) What is meant by DNA profiling?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
DNA profiling is a technique used to analyze the unique patterns of an individual's DNA. It is often utilized to identify individuals in forensic science or to establish paternity and maternity relationships.
Step 8
There are four bases in DNA structure: (v) In DNA profiling, what is used to cut the DNA strands into fragments?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In DNA profiling, enzymes known as restriction endonucleases are used to cut the DNA strands into specific fragments.
Step 9
There are four bases in DNA structure: (vi) Give two applications of DNA profiling.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Two applications of DNA profiling include forensic analysis to solve crimes and paternity testing to establish familial relationships.
Step 10
In humans, sex is determined by genes located on pairs of chromosomes called sex chromosomes: (i) The genotypes and matching phenotypes of the parents.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Assuming the parents are heterozygous for sex determination, the genotypes are XX (Female) and XY (Male). The matching phenotypes are Female and Male, respectively.
Step 11
In humans, sex is determined by genes located on pairs of chromosomes called sex chromosomes: (ii) The possible genotypes of the gametes that can be produced by each parent.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The female parent (XX) can produce gametes with the genotypes X and X. The male parent (XY) can produce gametes with the genotypes X and Y.
Step 12
In humans, sex is determined by genes located on pairs of chromosomes called sex chromosomes: (iii) The genotype of the offspring.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The possible genotypes of the offspring are XX (Female) and XY (Male). This demonstrates an equal chance of the child being male or female.
Join the Leaving Cert students using SimpleStudy...
