lecture 8

Question 1

What is non disjunction and where does it occur?

Answer 1

When too many chromosomes are being pulled on one end of the cells and none on the other side of the cells. This problem becomes noticeable in the anaphase.
Non disjunction can happen in meiosis II. Hapolid cells that have odd number of chromosomes can result from non disjunction.

Question 2

What happens when meiosis goes wrong?

Answer 2

Meiosis makes mistakes. When meiosis makes mistakes it can have big consequences on the gametes.

Question 3

What can non disjunction do in spermatogenesis?

Answer 3

In spermatogenesis it can give odd number of chromosomes.

Question 4

How many homologous pairs of chromosomes do humans have?

Answer 4

Humans have 23 homologous pairs of chromosomes. Autosomes are numbered from largest to the smallest 1-22.

Question 5

What can result in down syndrome?

Answer 5

Having 3 of chromosome 21 can result in down syndrome. Trisomy 21

Question 6

What is independent assortment?

Answer 6

Heterozygote at two loci can produce four different combinations of alleles that are equally likely that is called independent assortment.

Question 7

Dependent assortment

Answer 7

Predicts that the inheritance of physical characteristics are linked during gamete formation. The combinations that happen are not equally likely.

Question 8

Why does linkage happens?

Answer 8

Linkage happens because of crossing over. Crossing over has generated new combinations. Some genotypes will be more common than others

Question 9

Independent assortment

Answer 9

Independent all combinations are equally as likely

Question 10

Linkage

Answer 10

not all combinations are as likely

Question 11

Where does crossing over happens?

Answer 11

Crossing over happens in the same chromosomes

Question 12

Example of non mendelian inheritance

Answer 12

Prokaryote with asexual reproduction
Bacteria are haploid, they go through binary fission and make a clone

Question 13

Plasmid

Answer 13

Plasmid extra loop of dna , the cells bump into each other a dna go through a phase of conjugation, they connect the plasma together, inherited

Question 14

Euglena

Answer 14

is diploid and it clones itself from the original cell.

Question 15

What can reproduce asexually?

Answer 15

Multicellular eukaryotes can reproduce asexually as well.

Question 16

how do some haploid eukaryote reproduce?

Answer 16

There are haploid eukaryote organisms that reproduce sexually.

Question 17

What are some definitions for DNA?

Answer 17

Deoxyribo Nucleic Acid, the genetic materials of all known cells. Sugar-phosphate backbone with nucleic acid bases. A Polymer of nucleotides, each with a sugar, phosphate and nucleic acid base.

Question 18

What parts are attached to each other in DNA?

Answer 18

The sugar and the phosphate are attached to each other

Question 19

What are the nucleic bases?

Answer 19

Nucleic acid bases are Thymine, Adenine, Cytosine, Guanine

Question 20

What do the nucleic acid bases form? what are they specific about?

Answer 20

The nucleic acid bases may from hydrogen bonds with each other because of their shape and their chemical processes. The Bases are very specific about which base they will form hydrogen bonds with.

Question 21

Adenine goes with

Answer 21

Thymine

Question 22

Guanine goes with

Answer 22

Cytosine

Question 23

What is a base pair?

Answer 23

Two nucleic acid bases that are held together by hydrogen bonds are called a base pair.

Question 24

How is DNA usually found?

Answer 24

DNA is typically found double stranded, with complementary strands held together by base pairs. The sequence on one base pairs complements the other base pair.

Question 25

What must happen with DNA for cell division?

Answer 25

DNA must be replicated for cell division.

Question 26

Enzyme

Answer 26

DNA polymerase, theres more than one type, it binds to a template strand and it brings in a a nucleotide, then it shifts over ans brings in another nucleotide. We end up with two double stranded DNA molecules. Base, sugar and phosphate shape.

Question 27

Shape and orientation of DNA

Answer 27

Double stranded DNA is anti-parallele its important because it constrains interactions with the DNA. DNA polymerase is constrained to go in a certain directions, some proteins pull the DNA apart. (Dont need to know this) Need to know there are consequences to the antiparallele DNA cell.

Question 28

Gene expression

Answer 28

is the process by which they influence the phenotype

Question 29

What does DNA control?

Answer 29

Dna controls the production of certain protein and then the proteins influence the traits
DNA → Protein—> Trait Occurs more or less constantly in living cells

Question 30

Examples of DNA → Protein—> Trait

Answer 30

Examples
ATAC—> iNSULIN
GCCT→ enzyme → Chlorophyl

Question 31

How are certain genes expressed? Give examples

Answer 31

Some genes are only expressed by certain cells. Some genes are only expressed at certain times. Example: ears being formed, alleles being expressed only at that time.

Question 32

What does RNA stand for?

Answer 32

RNA (Ribo Nucleic Acid)

Question 33

DNA and RNA

Answer 33

DNA and RNA are similar
Both can be describe as a polymer…
They have a different sugar in RNA
RNA IS single stranded and DNA is double stranded

Question 34

Differences in DNA and RNA

Answer 34

One of the four bases is different for RNA, Thymene is never found in RNA and ONLY IN DNA you find Uracil instead.

Question 35

What are the three functions of RNA in the cell?

Answer 35

Messenger RNA (mRNA) carries a protein blueprint from DNA to ribosomes.

Transfer RNA (tRNA) Carries aminoacids to ribosomes

Ribosomal (rRna) With certain proteins, makes up ribosomes.