Science Exam Prep

• feature: a characteristic all members of a species have in common.

  ex: humans have hair, two eyes, a nose, two arms, and skin.

  ex: dogs have fur, a tail, 4 legs, teeth, a snout, and two eyes.
• trait: the individual expression/characteristics of a feature

  ex: humans have hair color, texture, thickness, eye color, and arm length

  ex: dogs have fur color, eye color, paw size, tail size, and thickness
• variation: all possible traits a feature can have
• heredity: the passing of traits from generation to generation

  - traits are determined by genetic information (DNA)
• gene: a section of DNA that carries instructions for a specific trait

  - DNA is packed together into chromosomes inside nucleus of every cell

  - each chromosome contains hundreds to thousands of genes

  - humans have 46 chromosomes (23 pairs)
• phenotype: the traits you observe about an individual

  - physical traits you have
• genes: inherited in pairs

  - 2 copies of each gene, 1 from egg, 1 from sperm
• genotype: all of the genes that make up an organisms DNA

  - we can also refer to the genotype for a specific trait

  - flower color = Ff/FF is purple, ff is white

  - stem length = LL/Ll is tall, ll is short
• allele: specific version or form of a gene

  - genes can have 2 or more alleles (versions)

  - code for a specific trait (1 for white flowers 1 for purple)

  - alleles do not have equal influence over a trait. some are more influential than others.
• total of chromosomes will always be an even number because 1/2 male part and 1/2 female part. chromosomes match in pairs.
• dominant: more influential allele (expressed in phenotype and represented in an uppercase letter)
• recessive: less influential allele (not able to be expressed through phenotype, represented with a lowercase letter)
• homozygous: when both alleles for a trait are the same
• heterozygous: when the 2 alleles for a trait are different
• punnet square: a mathematical model that allows us to predict how the alleles from 2 parents might combine
• structure: tissue, organ, or other formation made up of different but related parts.

  - physical formation
• function: special action of an organ or a body part or the purpose of a behavior

  - job/purpose
• behavior: manner of acting

  - way of acting
• insects structures and functions:

  - animals

  - multicellular

  - invertebrates (no backbone)
• exoskeleton: made of strong lightweight material (chitin)

  - protects internal organs, anchors muscles, keeps insect from drying out.
• segmented body (3 parts)

  • head: has eyes, antennae, and mouth parts

  - to eat food, see things, and sense things

  • thorax: three segments, 1 pair of legs attached to each segment

  - supports legs that are attached to each segment

  • abdomen: contains guts, modified heart, intestines, and reproduction organs. - circulatory system, carries O2 to each cell
• One pair of antennae

  - always a pair. differ from male to female.

  - sense odors and vibration
• simple and compound eyes:

  - two large compound eyes with up to 25,000 lenses

  - smaller eye often located on forehead

  - compound = lenses detect color and motion

  - simple = lenses register light instensity
• pulling antennae through mouth

  - to get nectar off so they can sense things clearly again; to clear senses
• spiracle: opening on the side of an insect's abdomen
• pheromone: chemical released by an animal to communicate with or influence another organism
• Cockroaches sometimes hiss in a presence of a female. (This could mean that it is a mating behavior) Also hissing could mean that the cockroach is trying to establish territory/scare of other males.

  Hissing is produced by forcing air out of spiracles on the fourth segment on their abdomen.
• Characteristics of life:

  Metabolism

  - gas exchange

  - need food

  - eliminate waste

  Growth/Development

  Respond to environent

  Made of 1 or more cells

  Maintain stable internal environment

  - need water

  Evolve/Adapt over time

  - species evolve, not individual

  Reproduction
• Living: displays all characteristics of life
• Nonliving: does not display all characteristics of life

  - never was living never will be
• Dead: once living but no longer displays characteristics of life
• Dormant: living but inactive, does not outwardly display all characteristics of life but has potential to do so given a suitable environment
• Red:

  Objective power: 4x

  Total magnification: 40x

  FOV: 4mm

  Yellow:

  Objective power: 4x

  Total magnification: 100x

  FOV: 1.5mm

  Blue:

  Objective power: 40x

  Total magnification: 400x

  FOV: 0.4mm
• Cell: basic unit of life

  - smallest unit that can demonstrate all characteristics of life

  Unicellular organism: one cell that can independently carry out all functions of life

  Multicelluar organism: many cells working together to carry out all functions of life. Individual cells cannot survive if separated from main organism.
• Cell theory:

  1. all living thing are made up of one or more cells
  2. cells are basic units of structure and functions in living things
  3. all living cells came from existing cells
• organism: any free living thing
• Plant cell: cell membrane, cell wall, chloroplasts, cytoplasm, endoplasmic reticulum, lysosomes (some), mitochondria, nucleus, no plasmids, ribosomes, vacuoles.
• Paramecia (protist cell): cell membrane. no cell way, chloroplasts (some), cytoplasm, endoplasmic reticulum, lysosomes, mitochondria, nucleus, no plasmids, ribosomes, vacuoles
• Animal cell: cell membrane, no cell wall, no chloroplasts, cytoplasm, endoplasmic reticulum, lysosomes, mitochondria, nucleus, no plasmids, ribosomes, vacuoles.
• Bacterial cell and Archean cell: cell membrane, cell wall, no chloroplasts, cytoplasm, no endoplasmic reticulum, no lysosomes, no mitochondria, no nucleus, plasmids, ribosomes, no vacuoles