Biology

Cell division

Cell division

The process by which a cell divides into two daughter cells.

Cell purpose (3 things)

1. Reproduce 2. Repair 3. Replace

Interphase Step 1

Growth (Gi). Cell grows in size and makes inmorpant parts needed for DNA replication.

Interphase Step 2

DNA replication. DNA must be copied before cell division.

Interphase Step 3

Growth (G2). Cell grows in size and checks to make sure cell is healthy before M phase.

Mitotic phase (M phase)

Cell divides, two identical daughter cells are created.

Mitotic phase in Prokaryotes

Prokaryotic cells divide by a process called binary fission.

Mitotic phase in eukaryotes

Mitosis is the process of dividing the nucleus. Cytokinesis is the process of dividing the eukaryotes.

Mitosis phases

Prophase, Metaphase, Anaphase, and Telophase

Prophase

DNA condenses in the nucleus to form visible chromosomes. Mitotic spindle forms cytoskeleton while nuclear membrane dissolves.

Metaphase

Chromosomes attached to the spindle fibers, move to the center of the cell. Chromosomes are now lined up in the middle of the cell.

Anaphase

Sister chromatids (identical chromosomes) are pulled apart to opposite sides of the cell.

Telophase

Sister chromatids are at opposite ends of the cell, nuclear membrane disassembles. Daughter cells reforms around each set of sister chromatids, forming new nuclei.

Cytokinesis

Cytoplasm divides, result of cytokinesis is two identical halves. Daughter cells of the mitotic phase have same number of chromosomes as the original.

Photosynthesis

photosynthesis is the process that allows plants to transform light energy into chemical energy.

Where does photosynthesis happen?

Photosynthesis takes place in the chloroplast of cells. A green pigment called chlorophyll is responsible for capturing the light energy.

What is chlorophyll?

Chlorophyll pigments absorb red and blue wavelengths of light well, and do not absorb green wavelengths. Insted it reflects it making it look green.

The chemical equation for photosynthesis

H

The Calvin Cycle

Uses ATP and NAD PH from the light dependent reactions to produce high energy sugars

Calorie

Is the amount of energy needed to raise the temp of 1 gram of water, 1 degree C.

Glycolusis

Releases only a small amount of energy. 1 molecule of glucose is broken producing 2 molecules (3 carbon compound).

NAD PLUS

In photosynthesis, each NAD+ accepts a pair of high energy electrons. NAD+ holds the electrons until transferred.

Fermentation

releases energy from food molecules by producing ATP in the absence of oxygen. Two Types: Alcohol and Lactic Acid

Anaerobic

Because fermentation does not require oxygen it is said to be anaerobic, which means “not in air”

Genetics

The scientific study of hereditary. Is now at the core of a revolution in understanding biology.

Fertilization

Produces a new cell, which develops into a tiny embryo encased within a seed. (Plants). 2 reproductive cells join in a process called fertilization. (Animals)

True Breeding

Meaning that if they were allowed to self pollinate, they would produce identical offspring.

Trait

Is a specific characteristic that varies from one individual to another.

Hybrids

The offspring is crosses parents with different traits

Genes

Are the chemical factors that determine traits

Alleles

Different Forms of a gene

Segregation

The separation of Alleles

Gametes

Formation of the sex cells

Probability

The likelihood that a particular event will occur

Punnett Square

Genetic cross can be determined by drawing a diagram known as a punnett square

Homozygous

Organisms that have two identical alleles for a particular trait (TT or tt)

Heterozygous

Organisms that have two different alleles for the same trait

Phenotype

Physical characteristics

Genotype

Genetic Makeup

Homologous

Each of the 4 chromosomes that came from the male parent have a corresponding chromosome from the female parent

Diploid

A cell that contains both sets of homologous chromosomes

Haploid

Organisms that contain one set of chromosomes and a single set of genes

Meiosis

The process of reduction division in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

Tetrad

Chromosomes pairs with its corresponding homologous chromosome to form a structure

Crossover

As homologous chromosomes pair up and form tetrads in meiosis, they exchange portions of their chromatids.

Allele

An Allele is a segment of DNA that codes for a particular trait. They are found in the chromosome. Humans have 46.

Homozygous

If an individual had two copies of the same allele they are considered homozygous for that trait.

Heterozygous

If an individual has two different copies of the same allele they are considered heterozygous for that trait.

Incomplete dominance

If a trait is exhibiting incomplete dominance, the dominant trait allele does not completely mask the recessive allele. Instead they are blending to create an intermediate phenotype.

Codominance

Codominance means there is more than one dominant allele. When both are inherited, both are expressed simultaneously.

Multifactorial

When the expression of a gene is influenced by the environment.

Necessary molecules of life

1. Carbohydrates 2. Fats 3. Proteins 4. Nucleic acid

4 DNA nucleotides (bases)

1. Adenine 2. Thymine 3. Cytosine 4. Quanine

Nucleotide

Long molecule of DNA

Antiparallel

Run parallel but in opposite directions

Leading strand and lagging strand

Leading - DNA polymerase continually makes strand

Lagging - DNA polymerase makes strand in sections called Okazaki fragments.

DNA polymerase

Responsible for adding on new nucleotides

Helicase

Responsible for separating the DNA strands

Function of DNA

To hold instructions needed for organisms

Function of RNA

To create proteins

Nucleotide 3 parts

5 carbon sugar, phosphate, nitrogen base

Gene

coded DNA instructions that control the production of protein

mRNA

RNA molecules carry copies of the instructions, they serve as messengers from DNA to the cell

rRNA

Ribosomes are made up of several dozen proteins called ribosomal RNA

tRNA

RNA molecules that transfers each amino acid to the ribosome

Transcription

RNA molecules are produced by copying part of the nucleotide sequence of DNA into a complementary sequence of RNA

RNA polymerase

During transcription, RNA polymerase binds to DNA and separates the DNA strands. RNA polymerase then uses one strandPromoters of DNA as a template from which nucleotides are assembled into one strand of RNA.

Promoters

The enzyme will bind only to regions of DNA known as promoters, which have specific base sequences.

Introns

Dna contain sequences of nucleotides, they are not involved in coding for proteins.

Exons

The DNA sequences that code proteins

Condon

Consists of three consecutive nucleotides that specify a single amino acid that is added to the polymerase.

Translation

During translation the cell uses information from messenger RNA to produce proteins.

Anticodon

These base called anticodon, are complementary to one more mRNA codon

What are mutations?

Mutations are changes in the genetic material

Deletions

Loss of all or part of the chromosome

Duplication

Produces extra copies of parts of a chromosome

Inversions

Part of a chromosomes becomes oriented in the reverse of it’s usual direction

Translocation

When part of the one chromosome breaks off and attaches to another

Taxonomy

How scientists classify organisms and assign each organism a universally accepted name

Binomial

Each species is assigned a two-part scientific name

Genus

The first part of a name is the genus to which the organism belongs

Taxton

The levels of the naming system