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Flashcards in Cells Deck (27):
0

Define the term chromosome

A chromosome is packaged and organized chromatin, a complex of macromolecules found in cells, consisting of DNA, protein and RNA.

1

Define gene

A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.

2

Define nucleotide

a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.

3

What are the structure and parts of a DNA nucleotide

Double helix
Sugar phosphate backbone
A amd t
G and c

4

What is the difference between a triplet and a codon.

Triplet is DNA
Codon is RNA
the triplet sequence in the messenger RNA (mRNA) transcript which specifies a corresponding amino acid (or a start or stop command).

5

What is the process of mitosis

Interphase -normal stage of cell
Prophase -DNA replicate and condenses into chromosomes
Metaphase -every chromosome lines up down the middle
Anaphase -centroph pull chromosomes apart
Telophase - chromosomes group in opposite poles
Cytokesis- cells split in 2 cells

6

What is the process of meiosis

Prophase
Metaphase
Anaphase
Telophase
Prophase 2
Metaphase 2
Anaphase 2
Telophase w

7

What is the difference between mitosis and meiosis

Mitosis-
A process of asexual reproduction in which the cell divides in two producing a replica, with an equal number of chromosomes in each resulting diploid cell.

Meiosis-
A type of cellular reproduction in which the number of chromosomes are reduced by half through the separation of homologous chromosomes, producing two haploid cells.


8

Define allele

An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome.

9

What is homologous

pairing at meiosis and having the same structural features and pattern of genes.

10

Define heterozygous

If an individual has two different alleles at a specific locus, the individual is heterozygous at that locus; i
Example
Ss
hH

11

Define homozygous

Zygosity is the degree of similarity of the alleles for a trait in an organism. Most eukaryotes have two matching sets of chromosomes; that is, they are diploid.

12

Define karyotype

the number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

13

Define diploid and haploid

Having the same number of sets of chromosomes as a germ cell, or half the diploid number of a somatic cell. The haploid number (23 in humans) is the normal chromosome complement of germ cells. n. Having a single set of each chromosome in a cell or cell nucleus.

14

Where is RNA made

Inside the nucleus

15

Where does RNA go after the nucleus

then mRNA is transported out of the nucleus into the cytosol, where it is translated to protein by ribosomes.

16

What is the process of transcription

Process by which genetic information in the DNA is transferred to RNA. DNA sequence is enzymatically copied by the RNA to produce a complementary nucleotide RNA.

17

How many nucleotides in the mRNA code for one amino acid

Three
- codon

18

What is the process of translation

Initiation: amino acid attaches and starts to scan for a start signal.
Elongation: A new tRNA+amino acid enters the ribosome, If its anticodon matches the mRNA codon it basepairs and the ribosome can link the two aminoacids together.The ribosome then moves one triplet forward and a new tRNA+amino acid can enter the ribosome and the procedure is repeated.
Termination: When the ribosome reaches one of three stop codons, for example UGA, there are no corresponding tRNAs to that sequence. Instead termination proteins bind to the ribosome and stimulate the release of the polypeptide chain (.


When the genetic code Carried by messenger RNA directs the production of proteins from amino acids

19

What is a somatic cell...in relation to diploid

any cell of a living organism other than the reproductive cells
Like all cells, somatic cells contain DNA arranged in chromosomes. If a somatic cell contains chromosomes arranged in pairs, it is called diploid and the organism is called a diploid organism.

20

What is a sex cell

A haploid cell is a cell that contains one complete set of chromosomes. Gametes are haploid cells that are produced by meiosis
reproductive cell: a spermatozoon or an ovum; a cell responsible for transmitting DNA to the next generation

21

Difference between haploid and diploid

Diploid just means that the cell contains two sets of DNA ("di" means two). Most cells in the body are diploid. The diploid number of chromosomes in a human somatic (body) cell is 46.

Haploid means that the cell contains one set of DNA, half of a diploid cell. The haploid number of chromosomes in a human body cell is 23. A human haploid body cell denotes a sex cell (i.e. sperm, egg).

22

Difference between recessive and dominant alleles

Dominant allele: A single copy of gene is enough to express its character. Usually denoted by capital letter
eg: Tall in pea plant (T) TT and Tt both are tall

Recessive allele: Two copies of the gene is necessary to express its character. Denoted by small letter
eg: Dwarf/short in pea plant
Only tt is short.

23

Difference between dominant and recessive inheritance, incomplete inheritance and co-dominant inheritance

Codominance - A form of inheritance in which both alleles are equally shown.
Incomplete dominance - A form of inheritance in which the heterozygous alleles are both expressed, resulting in a combined phenotype.

Recessive Inheritance
Both parents carry a normal gene (N), and a faulty, recessive, gene (n). The parents, although carriers, are unaffected by the faulty gene. Their offspring are affected, not affected, or carriers. This type of inheritance was first shown by Mendel.

Dominant Inheritance
One parent has a single, faulty dominant gene (D), which overpowers its normal counterpart (d), affecting that parent. When the affected parent mates with an unaffected and non-carrier mate (dd), the offspring are either affected or not affected, but they are not carriers.

24

Difference between dominant and recessive inheritance

Recessive Inheritance
Both parents carry a normal gene (N), and a faulty, recessive, gene (n). The parents, although carriers, are unaffected by the faulty gene. Their offspring are affected, not affected, or carriers. This type of inheritance was first shown by Mendel.

Dominant Inheritance
One parent has a single, faulty dominant gene (D), which overpowers its normal counterpart (d), affecting that parent. When the affected parent mates with an unaffected and non-carrier mate (dd), the offspring are either affected or not affected, but they are not carriers.

25

What is the ounnet square

The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C.

26

Phenotype

Characteristic or trait influenced by genotype