Plant Science Test 3

Chromosomes

carry most of the genetic information plants, transmit genetic information from one generation to the next, same chromosomes in all vegetative cells of a plant

Chromosome components

Long chains of DNA, associated RNA and various proteins, replicate themselves, 2 spiral strands of DNA linked together

DNA

attached by hydrogen bonds between organic bases, Cytosine and Guanine, Adenine and Thymine, always bond in same pattern

Homologous chromosomes

diploid cells are paired, each chromosome in a pair carries the same genes affecting the same traits as the other

DNA replication

strands break along the organic base bonds, each base reattaches to its complementary base (sugar/phosphate), two new identical double strands are created

Mitosis

cell division in vegetative cells, prophase, metaphase, anaphase, telophase, cytokinesisM

Meiosis

occurs in reproductive cells to form pollen grains and the egg, steps are like mitosis, but there are 2 rounds of chromosome separation

Interphase

homologous chromosomes align across from each other, one set is from the male parent of the plant and the other set is from the female parent, alignment of chromosomes is random

Meiosis 1

chromosomes double and separate, resulting in two diploid cells

Meiosis 2

chromosomes mix up and separate, resulting in four haploid cells, chromosomes may have any combination of genes from the grandparents

Genes

triplet sets of organic bases along a DNA molecule that code fro specific traits that are passed to successive generations, on the same chromosome are linked and usually carried together from one cell generation to the next

Alleles

corresponding genes on a pair, alternative forms of a gene

Heterozygous

different alleles at the same locus

Homologous

same allele on each homologous chromosom

Dominant traits

capitalized letter

Recessive Traits

lowercase letter

Genotype

genetic makeup of the plant, the alleles present for each gene

Phenotype

plant’s appearance, or results of expression of the gene activity and interaction with the environment

Gene expression

process that activates transcription of genes into mRNA followed by translation of mRNA into amino acid sequences

Factors of gene expression

environmental signals, plant age, position of cell in the plant

Why do we name plants?

communication and categorization

Why use common names

the ability to communicate with the general population

problems with common names

different languages and cultures have different names for the same plant

Classification of naming in order

domain, kingdom, phylum/division, class, order, family, genus, species

Kingdom examples

plantae, animalia, fungi, Protista, bacteria/eubacteria, archaea

plantae

secondary growth, cell walls, polyploidy, autotrophic nutrition(photosynthesis)

animalia

no cell walls, heterotrophic nutrition

Phylum examples

bryophyte, hepaticophyta, coniferophyte, ginkgophyte

Family

closely related genera grouped together based on similar or chemical characteristics, all names end with aceae, first letter is always capitalized or entire word

Binomial nomenclature

system developed by Gaspard Bauhin and Carl von Linne for naming and classifying plants

Two main parts of binomial scientific names

genus and species

Genus

relatively small group of closely related plants that share the general characteristics

species

comprised of plants possessing unique and essentially identical morphological and phylogenetic characteristics and are capable of interbreeding among themselves

Variety

variation within a species that arose naturally

cultivar

variation within a species that arose or was bred in cultivation

Basic photosynthetic equation

CO2+H2O ——> C(H2O)n+O2

Where does photosynthesis occur?

upper 40% of leave in the palisade parenchyma and chloroplast

structures in chloroplasts

thylakoid, granum, stroma lamellae

Thylakoid

vesicle with chlorophyll and other compounds required for photosynthesis embedded in its membrane, biochemical reactions that transform CO2 into carbohydrates occur inside lumen

Granum

stacks of thylakoids

stroma lamellae

connection between thylakoids in adjacent granum stacks

where does CO2 come from?

atmosphere and enters open stomata

what is CO2 used for

source of carbon and oxygen for carbohydrate

Where does water come from?

take up from reserves in soil by roots, distributed to leaves through xylem

what is water used for

supplies electrons for converting light energy into stores energy, supplies hydrogen for making carbohydrates, source of oxygen in equation

role of light

supplies energy for making carbohydrates

role of chlorophyll

absorb red and light energy, aid in the conversion of light energy into biochemical energy, transfer light energy to a storable form

photosystem 2

specialized chlorophyll (P680), hydrolysis of water, transfers light energy received from harvesting chlorophyll to electrons derived from water, generates ATP

Photosystem 1

P700, received electrons from photosystem 2, generated NADPH

Why is CO2 important

used for carbohydrates in the Calvin Cycle, energy from light reactions are used to fuel the process

First reaction of Calvin cycle

RuBisCO enzyme

What is created from the first Calvin Cycle reaction

2 molecules of 3-PGA

What is the most abundant enzyme on the Earth

RuBisCo

Light Reaction 1

3-PGA, ATP, 3-Bisphosphate, ADP

Light Reaction 2

3-Bisphosphoglycerate, NADPH, NADP, Glyceraldehyde -3phosphate

Examples of C3 plants

soybeans, tobacco, cotton, melons, roses, potato, tomato, bentgrass, wheat, oats, alfalfa

What is the most limiting environmental factor in photosynthesis?

light

Light Compensation point

Photosynthesis and respiration are equal and net gas exchange is zero

Light saturation

increases in light intensity will not increase photosynthesis activity

Second most limiting factor in photosynthesis

CO2 (0.03% of gas in atmosphere)

What is the optimum temperature for photosynthesis

25-30 or about 38 for higher levels of CO2

How much water is used in photosynthesis

less then 0.1%

what water is used for

transpiration, stomatal activity, chemical reactions, and maintain structure

impacts oxygen has on photosynthesis

competes with carbon dioxide for binding site on the Rubisco enzyme

C3 plant anatomy

small BS cells/ no chloroplast, 3PGA, RUBISCO in leaf mesophyll, cold season plants

C4 anatomy

large BS cells with chloroplasts, OAA, leaf mesophyll use PEP Carboxylate to fix CO2, RIBISCO enzyme in BS cells, warm season plants

First reaction in C4 plants

atmospheric CO2 combined with PEP to make oxalacetate

second reaction in c4 plants

oxalacetate is converted to malate, NADPH from light reactions is used

third reaction in C4 plants

malate is tranported to bundle sheath chloroplasts

fourth C4 reactions

malate is broken down into pyruvate and CO2

example of C4 plants

corn

CAM plant

Crassulacean acid metabolism, used PEP carboxylase, opens at night, used OAA

Basic Respiratory Equation

C(H2O)n +O2 ——> CO2+H2O +energy

Where does carbohydrates come from in the respiration equation?

photosynthesis, store food reserves

What does metabolism of carbohydrate produce?

CO2, Energy→ ATP and NADH

Where does oxygen come from in the respiration equation

atmosphere

What is the oxygen used in the respiratory equation used to produce?

water in the mitochondria

Metabolism of Carbohydrates

glycolysis, citric acid cycle, electron transport chain

Where does glycolysis occur

cell cytoplasm

which carbohydrate beings the citric acid cycle

glucose

products of glycolysis

2 molecules of pyruvic acid and ATP

Location of Citric acid cycle

mitochondria

which carbohydrate begins the citric acid cycle

pyruvate

products of the Citric Acid Cycle

3 molecules of CO2 from each pyruvate, ATP, FADH, NADH

electron transport location

occurs in cell mitochondria inner membrane

Electron transport chain process

energy compounds (NADH and FADH) and oxygen, produces water and ATP energy (3 NADH and 2 FADH)