BY 124 SI WORKSHEET 2

Terms

Double Fertilization

Two sperm cells enter the female gametophyte, one fertilizes the egg (diploid zygote) and the other fuses with the two nuclei in the large central cell of the female gametophyte, producing a triploid cell.

Taproot

Root system consisting of a main vertical taproot which develops from the embryonic root. Gives rise to lateral roots or branch roots. Can penetrate deeper into the ground and adapt to deeper sources of water.

Nodes

The points on a stem where leaves are attached. Internodes are the spaces between nodes

Ground tissue system (2 types)

Tissue that is neither vascular nor dermal. Main role is nutrient storage and photosynthesis. (parenchyma cells). 2 types: pith – ground tissue that is internal to the vascular tissue. Cortex – ground tissue that is external to the vascular tissue.

Apical dominance the inhibition of axillary buds by apical buds. Proximity of axillary buds to apical buds is responsible for their dormancy. If an animal eats the end of a shoot or the sun doesn’t reach the top but reaches the sides, axillary buds break their dormancy (example: pruning trees)

Parenchyma cells

Primary cell walls are thin and flexible, lack secondary cell wall. Large central vacuole. Least specialized of all plant cells. Perform most of the metabolic functions of the plant, synthesizing and storing organic products. Fleshy tissue of many fruits are parenchyma cells. Most retain the ability to divide and differentiate into other cell types. Alive at maturity.

Sieve tube elements long narrow tubes that transport nutrients. ST elements lack a nucleus, ribosomes, a vacuole, and a cytoskeleton enabling nutrients to pass more easily through the cell. Sieve plates have pores that facilitate the flow of fluid from cell to cell. A companion cell is alongside each ST element and helps serve the ST element and do the things it can’t since it lacks so many cellular components

Anther

Part of the flower where pollen is produced. A component of the stamen

Meristem perpetually undifferentiated tissues that divide when conditions permit. Cork Cambium

Lateral meristems that contribute to the thickness of woody plants. Contribute to secondary growth. The cork cambium is responsible for replacing the epidermis with the thicker tougher periderm.

Stoma pores on the epidermis that allow for transfer of gasses between the plant and the atmosphere. Also a major avenue for evaporative loss of water. Opening and closing regulated by guard cells

Short Answer

Describe the difference between determinate and indeterminate growth.

Indeterminate - growth occurs throughout the plants life cycle

Determinate - plants stop growing after they reach a certain size

What are the 3 categories of flowering plants?

Annuals – complete their life cycle in a year or less

Biennials – require two growing seasons

Perennials – life cycle over many years

What are the ways that monocots and dicots are distinguished from one another.

Cotyledons: Monocots have one dicots have two Leaf ventilation: monocots have parallel veins and dicots have a net-like veins Vascular tissue in the stem: monocots scattered dicots arranged in a ring Roots: monocots have fibrous roots with no main root, dicots have a taproot system present Pollen grain: monocots have one opening in pollen grains and dicots have three Flowers: monocots have floral organs arranged in groups of 3’s, dicots are arranged in groups of 4’s or 5’s

What are the two types of vascular tissue and what are their components?

Xylem - Tracheids and vessel elements are water-conducting, tubular, elongated cells that are dead at maturity. Tracheid secondary walls lined with pits that expose primary cell wall and allow for water transfer between cells. Tracheids are long, thin and tapered with water moving between pits. Vessel elements are wider, shorter and thinner walled, forming long micropipes called vessels. These have perforations that allow water to flow through. Secondary walls of both types of cells are hardened with lignin. Phloem - Unlike xylem alive at functional maturity. Sieve cells and Sieve tube elements are long narrow tubes that transport nutrients. ST elements lack a nucleus, ribosomes, a vacuole, and a cytoskeleton enabling nutrients to pass more easily through the cell. Sieve plates have pores that facilitate the flow of fluid from cell to cell. A companion cell is alongside each ST element and helps serve the ST element and do the things it cant since it lacks so many cellular components

What type of plant is this (monocot, dicot) and how can you tell?

It is a monocot root. The vascular tissue is arranged in a circular ring around the center which is indicative of a monocot.