Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology 30-1 > Unit 3 gene part 2 chromosomes and Genes > Flashcards

Unit 3 gene part 2 chromosomes and Genes Flashcards

1
Q

what is a monohybrid cross?

A

cross of two individuals that differ in one trait

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

what is a dihybrid cross?

A

a cross of two individuals that differ in two traits

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

What does Mendel’s first law state? ( The law of segregation?

A

Mendel’s law states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete

( all individuals have two copies of each factor.. (genes). These copies segregate (separate) randomly during gamete formation, and each gamete receives one copy of every factor.

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

Allele

A

the singular letter present in a genotype is called an allele
capital letter- dominant
lowercase letter - recessive

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

what is genotype

A

the from expressed for genes in letter
ex. AAbb or AaBb

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

what is phenotype

A

the form to express a trait in physical form.
ex. purple, red

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

what is the meaning of homozygous?

A

An organism that has two identical alleles for a trait
ex. RR or rr

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

what is heterozygous?

A

an individual with two different alleles for a trait.
ex. Rr

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

what is the law of independent assortment?

A

the law that states that genes separate independently of one another in meiosis

( the two alleles for one gene segregate (assort) independently of the alleles for other genes during gamete formation)

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

what is the law of dominance?

A

recessive alleles will always be masked by dominant alleles

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

What is a testcross?

A

A cross involving the unknown organism with a homozygous recessive organism

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

If recessive traits show up in the first generation of a testcross then the unknown must have been what?

A

heterozygous

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

If nothing but dominant traits appear in F1 and successive generations, then the unknown is most likely what?

A

homozygous, purebred, true-breeding

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

What is Type III- incomplete dominance?

A

The heterozygous genotype yields a third phenotype that is a blending of the dominant and the recessive alleles. Includes color, shape, and severity of disease.

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

What is Type IV- Codominance?

A

Hetrozygous genotype yields a third phenotype that is an equal expression of both alleles. Get roan coats, red and white colours, blood Type AB

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

Type V- Lethal alleles

A

when gene is homozygous (either dominant or recessive), it can cause death. If lethal allele is dominant, then individual with GG will die. if lethal allele is recessive, then individuals with gg will die.

Creeper chickens, Manx cat, cystic fibrosis, sickle cell anemia

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

What is the method for writing genotypes for Linked genes ?
Femals and males with a disease inheritance…?

A

These diseases are only places on the X chromosome thats why they are referred as X-linked inheritance

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

what is multiple alles?

A

a gene with more than two alleles

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

What is X-inactivation inheritance?

A
  • occurs when one copy of the X chromosomes is inactivated
  • prevents females from having too many gene products (dosage compensation)
  • which X becomes inactive is random during embryonic development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are autosomal linked genes?

A

autosomal linked genes are genes that are located on the same chromosome from chromosomes 1 through to 22. They are except from crossing over and tend to be inherited together.
- Defies Mendel’s law of independent assortment
- monohybrid pattern

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

What are unlinked genes ?

A

genes located on different chromosomes
- dihybrid pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the impact of gene linkage?

A

you loose variety

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the benefits of gene mapping?

A
  • allow us to understand the overall complexity and genetic organization of a particular species
  • improve out understanding of the evolutionary relationships among different species
  • used to diagnose, and, someday to treat inherited human diseases
  • predict the likelihood that a couple will produce children with inherited diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The higher the crossover frequency between two genes, the what???

A

the further apart they must be on the chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is recombinant types ?
F1 generation have different combination of alleles than the chromosomes of the P generation.
26
what is recombination frequency?
the percentage of times that a crossover occurred as P gametes were formed.
27
what is the formula for recombination frequency?
Number of recombinant types __________________ x 100% Total number of offspring
28
smaller the crossover rate the _____ the genes are?
closer
29
What is the pattern of inheritance for Autosomal Dominant ? (Aa OR AA)
- due to a dominant allele carried on one of the autosomes (e.g tongue rollers, widow's peak) - affected child has affected parent - males and females are affected equally - 2 unaffected parents will not have affected children - huntington disease- common autosomal dominant disorder
30
what is autosomal recessive (aa) inheritance pattern?
- due to recessive alleles carried an autosome (e.g attached earlobes, curved thumbs) - individual must inherit a recessive allele from each parent - individual will be a "carrier" if they are (Aa) Cystic fibrosis...
31
X- linked recessive (X^bY or X^b X^b) inheritance pattern?
- more males than females are affected as they only need one recessive allele - an affected female has an affected father - an affected women will have all affected sons - characteristic often skips a generation from the grandfather to the grandson ex. Hemophilia
32
X-linked dominant ( X^BY, X^BX^B, X^BX^b) inheritance pattern?
- rarest of all inheritance types - gene on the X chromosome so no transmission from father to son - affected males produce affected females - since females have 2x chromosomes they are more likely to be affected X-linked dominant disorders are not very common
32
who was Fredrick Griffith?
Proved a process called transformation: genetic material from one cell can be transferred to another cell.
33
Oswald Avery
Discovered that the nucleic acid in DNA stores and transmits genetic information from one generation of bacteria to the next.
34
who is Alfred Hershey and Martha chase ?
used radioactive markers in experiments to show that DNA was the genetic material in cells
35
Ervin Chargaff
defined the rule that the %A=%T and %G=%C in all double stranded DNA genomes
36
Rosalind Franklin
Woman who generated x-ray images of DNA, she povided Watson and Crick with key data about DNA -Used X-ray diffraction to discover the double-helical structure of DNA. - she concluded that the nitrogenous bases were located on the inside of the helical structure, and the sugar-phosphate backbone was located on the outside, facing toward the watery nucleus of the cell.
37
who was James watson and francis crick?
1953. Built first accepted DNA model explaining specific structure and properties of DNA. - discovered that an A nucleotide on one chain always sits across from a T nucleotide on the other chain, while a C nucleotide on one chain always sits across from a G nucleotide. A-T C-G
38
Complementary base pairs?
A-t C-g these are held together by hydrogen bonds single base is always paired with a double base
39
What does it mean when DNA strands are Antiparallel?
Strands parallel to each other going in opposite directions (3'-5' and 5'-3')
40
What are the single ringed N-bases called?
thymine and cytosine (Prymidines)
41
what are the two double- ringed N-bases called?
Adenine and Guanine (purines)
42
What is the basic building block of DNA?
nucleotide
43
What are the three components of a nucleotide?
1. phosphate base 2. deoxybrose sugar 3. nitrogen base (a,t,c,g)
44
what is a double helix?
two strands of nucleotides wound about each other; structure of DNA
45
What are the five main features of the DNA model?
1. the DNA molecule (chromosome) consists of two strands coiled around one another 2. The deoxyribose sugar-phosphate backbone of the stand is the outer portion of the molecule 3. the N-base extends inward off each deoxysugar molecule and is held together by weak hydrogen bonds. The molecules within the nucleotide are held together by covalent bonds 4. the base pairing occurs between A-T AND C-G 5. the two strands run antiparallel to one another, phosphate = 5" end, deoxybrose sugar = 3" ends
46
what is RNA and how does it differ from DNA?
- It is still found in the nuclei like DNA but has three key differences: 1. the sugar componenet of RNA is ribose rather than deoxyribose. 2. RNA does not have the nucelotide thymine (T) in its place is the nucleotide uracil (U). 3. RNA remains single stranded, although the single stand can sometimes fold back on itself to produce regions of complementary base pairs
47
Mitochondrial DNA (mtDNA)
genetic material in the mitochondria of the cytoplasm of a cell; only inherited from the mother
48
Why is mitochondrial DNA only passed from the mother?
since sperm have no mitochondria, inheritance is purely maternal - the midsection of the sperm does not pass during fertilization
49
what is the genome of an organism?
is the sum of all the DNA that is carried in each cell of an organism.
50
What is replication?
is the process of creating an exact copy of a molecule of DNA.
51
What is the first step of DNA replication and what happens during this process?
the first step is called helicase: - A group os enzymes called helicases, bind to the DNA at the replication origin. The helicase breaks the H-bonds between N-bases and creates a Y-shaped areas called replication forks. - unwinding or unzipping DNA.
52
What happens during the DNA molecule during the second step of DNA replication?
DNA polymerase base pairs the exposed N-bases in the leading continuous strand (5' to 3') and the lagging discontinuous strand (Okazaki 3' to 5' fragments)
53
What happens during the third step of DNA replication?
Ligase adds the deoxyribosephosphate backbone completing the polynucleotide DNA. Proofreader enzymes check for mismatched pairs and correct
54
what is semiconservative replication?
when replication takes place in DNA while conserving the old stand and replicating and creating a new strand
55
What is elongation?
the process of joining nucleotides to extend a new stand of DNA happens during the second step of DNA replication. - can only take place in the 5' to 3' direction - this is known as the leading stand
56
what is termination in DNA replication?
The completion of the new DNA strands and the dismantling of the replication machine ( complex of polypeptides and DNA that interact at the replication fork is known as a replication machine)
57
#58 Draw out Semi-conservative
58
how is DNA and mRNA different ?
DNA - can replicate - double stranded - thymine present - pentagon shaped deoxyribose sugar - found in the nucleus RNA - comes from DNA - Cant replicate - single stranded - Uracil replaces thymine - pentagon shaped ribose sugar - made in the nucleus works in the cytoplasm
59
what step of meiosis does DNA turn into mRNA turn into Protein?
G1
60
what is a codon?
3 consecutive N-bases, codes for one amino acid pairing
61
What happens during transcription? (this is seen when converting DNA to protein)
- this takes place in the nucleus - how?: 1. one DNA stand acts as the sense strand. This is the code for the gene. Therefore, to express the correct gene, the DNA is read 3' to 5' 2. RNA polymerase base pairs those in the RNA molecule using the antisense strand (DNA STRAND). The mRNA is transcribed in the 5' to 3' direction 3. Phosphates and sugars are added to complete the mRNA
62
Explain mRNA processing?
Before mRNA can leave the introns (useless sequences of nitrogen bases), must be removed. Enzymes, called restriction enzymes, perform this task. Exons (useful sequences of N- bases) are then spliced together using ligase enzymes. We now have a fully functioning mRNA capable of making proteins.
63
Define translation?
mRNA converted into an amino acid sequence that becomes a protein
64
What is initiation (first step of translation)?
- AUG start codon; ribosome reads the mRNA in the 5’ to 3’ direction - mRNA is attached to a subunit of the ribosome, the first codon is always AUG
65
What is elongation (step two of translation)
Addition of amino acids connected together by strong peptide bonds for entire length of the mRNA; tRNAs bring in the proper amino added to the growing polypeptide chain.
66
What is termination (still step 2 of translation) ?
occurs when a stop codon in the mRNA reaches the A site of the ribosome - stop codons; stops protein synthesis; at end of the gene code for this trait
67
Define an anticodon?
transfer RNA - picks up free floating amino acids in the cytoplasm and transport them to their correct spot in the mRNA sequence. - each term has an anticodon which simply runs antiparallel in the mRNA codon for correct base pairing.
68
What type of bond holds the amino acids together?
peptide bonds holds amino acids together
69
What type of bonds keep the structures of a nucleotide together?
covalent
70
what tyoe of bond keeps the base pairs together?
hydrogen bonds the weakest bond
71
#72 explain and draw out protein synthesis

Biology 30-1 (11 decks)

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